The Bay Area Water Supply and Conservation Agency (BAWSCA) typically conducts an annual survey of its members in order to update key agency-wide information and assist in projecting wholesale customer water demands and population. Summarized below and included in the following pages in written, tabular, and/or graphic form are the most pertinent and interesting highlights of the FY 2010-11 survey.
Past, Current and Projected SFPUC Purchases
Current Water Purchases from SFPUC
BAWSCA agencies reported SFPUC purchases of 144.9 mgd in FY 2010-11, including supplemental water purchases of 2.18 mgd, down slightly from the total 150.65 mgd purchased in FY 2009-10. Compared with the 10 year average, purchase levels in FY 2010-11 were below average by 17.4 mgd. Since FY 2006-07, purchases have fallen 26.4 mgd. The highest single year occurred in FY 1986-87 when 184.8 mgd was purchased from the SFPUC.
Projected Water Purchases from SFPUC
As part of its action on the Program Environmental Impact Report (PEIR) for its Water System Improvement Program (WSIP), the San Francisco Public Utilities Commission made the decision to limit wholesale customer purchases from the regional water system to 184 mgd and retail customer purchases from the regional water system to 81 mgd through 2018.
Total Water Suppy and Demand

Current BAWSCA-Wide Total Water Demand Compared to Pre-Drought Conditions
For 2010-11, total demand was 223 mgd. In response to drought conditions, voluntary water conservation targets of 10% were initiated during Summer 2007, and continued in 2011. In comparison, in FY 1996-97, BAWSCA-wide demand, including demand for sources in addition to the regional water system, equaled the pre-drought demand of FY 1986-87 at 260 mgd.
Meeting Projected BAWSCA-Wide Total Water Demand
In FY 2008-09, BAWSCA and its member agencies initiated the development of a long-Term Reliable Water Supply Strategy (Strategy) to meet the projected water needs of its member agencies and their customers through 2035 and to increase their water supply reliability under normal and drought conditions. The Strategy is proceeding in three phases. Phase I was completed in June 2010 and defined the magnitude of the water supply issue and the scope of work for the Strategy. Phase IIA of the Strategy is currently under development and will result in a refined estimate of when, where, and how much additional supply reliability and new water supplies are needed throughout the BAWSCA service area through 2035, as well as a detailed analysis of the water supply management projects, and the development of the Strategy implementation plan. Phase IIA will be complete in Summer 2012. Action by the BAWSCA Board to implement recommendations from Phase IIA is anticipated in Fall 2013.
Current Water Supply by Source
BAWSCA’s historical sources of supply vary little from one year to the next. Of the total amount of water used by BAWSCA agencies in FY 2010-11, 65% came from the SFPUC, 13% from groundwater, 16% from other sources (Santa Clara Valley Water District and the State Water Project), 3% from local surface water (primarily ACWD’s take from Lake Del Valle), and 3% from recycled water.
Current Water Use by Class of Customer
As with the source of supply, BAWSCA’s demand by customer class varies little over time. Among BAWSCA agencies in FY 2010-11, the residential sector accounted for 58% (131 mgd) of the 223 mgd consumed; commercial and industrial customers, 21% (46 mgd); government/other, 4% (9 mgd); dedicated irrigation, 9% (21 mgd), and unaccounted-for water, 8% (17 mgd). In FY 2010-11, there were 429,953 accounts (service connections) in the entire BAWSCA service area, 87% or 376,061 of which were residential (see Notes next page).
Current and Projected Population

The population of the BAWSCA service area decreased from 1,719,028 to 1,701,756 between FY 2009-2010 and FY 2010-11.
Climatological Data
In the three years leading up to FY 2009-10, rainfall totals were lower than the historical average. Rainfall for both FY2009-10 and FY2010-11 were higher, however. Rainfall recorded at 4 locations in the BAWSCA service area for FY 2010-11, recorded levels approximately 1 inch over the historical average.
Current Water Use Per Capita
Average residential per capita consumption (excluding Stanford) in the BAWSCA service area was 77 gpcpd in FY 2010-11, unchanged from the year before. This is 25% less than the estimated 104 gpcpd that was experienced during pre-drought FY 1986-87 and 32% less than the 115 gpcpd in pre-drought FY 1975-76. In FY 2010-11, among BAWSCA agencies, Westborough WD had the lowest residential per capita consumption at 43.3 gpcpd while Purissima Hills had the highest at 263.1 gpcpd. The average gross per capita consumption of the BAWSCA service area in FY 2010-11 was lower than that of FY 2009-10 – 127 gpcpd compared to 130 gpcpd. FY 1985-86 (pre-drought) gross per capita was 182 gpcpd.
Single Family Water Bills (as of July 2010) /Water Rate Structure

Water bill data has been calculated using each agency’s single family average monthly use. This information is summarized in Section 8. Among BAWSCA agencies, the average monthly bill ranged from a low of $27.12 in North San Jose for 8.7 units to $166.94 for 27.5 units in Hillsborough. The average single family water bill among all BAWSCA agencies inclusive of the service charge was $52.49. Average monthly residential use varied from 5.0 units (Brisbane/GVMID) to 31.8 units (Purissima Hills). Average monthly service charge was $11.41, ranging from a low of $4.50 (Hayward) to a high of $31.10 (Burlingame).
Of 24 wholesale customers surveyed regarding water bills, six (ACWD, Burlingame, East Palo Alto, Millbrae, Santa Clara, and Westborough) have a uniform rate structure (same rate per unit of water for all volumes used). The remaining 18 agencies have inclined block rate structures (rate per unit increases as use increases).
Agency Profiles
Agency profiles Agency profiles were updated based on revisions supplied by agency representatives.
